Orange S.A.

About: Orange S.A. is a company organization based out in Paris, France. It is known for research contribution in the topics: Terminal (electronics) & Signal. The organization has 6735 authors who have published 9190 publications receiving 156440 citations. The organization is also known as: Orange SA & France Télécom.

20 Gbit/s operation of a high-efficiency InGaAsP/InGaAsP MQW electroabsorption modulator with 1.2-V drive voltage

Abstract: The authors have fabricated a ridge waveguide electroabsorption modulator based on the quantum-confined Stark effect in InGaAsP/InGaAsP multiple quantum wells. The drive voltage for 12-dB extinction ratio is 1.2 V, and the frequency response is flat within 2 dB from DC to 20 GHz. Operation at 20 Gb/s is reported. Extensive data concerning the parasitic phase modulation (chirping) are obtained as a function of applied bias acid operating wavelength. >

Blind adaptive channel estimation in ofdm systems

Abstract: We consider the problem of blind channel estimation in zero padding OFDM systems, and propose blind adaptive algorithms in order to identify the impulse response of the multipath channel. In particular, we develop RLS and LMS schemes that exhibit rapid convergence combined with low computational complexity and numerical stability. Both versions are obtained by properly modifying the orthogonal iteration method used in numerical analysis for the computation of singular vectors. With a number of simulation experiments we demonstrate the satisfactory performance of our adaptive schemes under diverse signaling conditions

Information-centric networking: a natural design for social network applications

Abstract: Millions of people now use online social network applications such as Twitter, Facebook, and Google+. This kind of application offers the freedom for end users to easily share contents on the Internet. In parallel with the expansion of OSNs, a new networking paradigm emerges, the information-centric networking approach, where the focus is on the content the user wishes to obtain instead of the server that provides this content: a content-based approach instead of a host-centric one. Looking at the ICN concept, and more precisely the CCN (which stands for content-centric networking) solution in this article (based on Interest-Data messages), and at OSNs behavior (users subscribing to contents posted by another user in case of Twitter, or the notion of friends receiving contents from others friends in Facebook), we advocate that the CCN paradigm perfectly fits with the OSN applications behavior and can help to save network load. In this article, we describe how OSN applications can run with the CCN solution and the evaluation we have performed highlights the benefit of using such a CCN approach compared to the current classical IP-based delivery and to the CDN-based solution, for the use-case of Twitter. Depending on the CCN nodes location and the cache efficiency, the network load can be significantly reduced and the response time to get the content can be faster up to 60 percent.

Pretense of intimacy in France

Abstract: Introduction In France the mobile phone, launched in 1987, developed slowly at first, before suddenly taking off in 1997. Since then its annual growth rate has been 120%, with the number of subscribers rising to 14 million in 2000, a little under 30% of the population. This success needs to be analyzed not only in light of the exceptional speed of diffusion but also because of the mass phenomenon (quantitative threshold) it expresses. For once, sociologists of technology are not asking the question: “What is curbing the adoption and use of the tool?” On the contrary, they are wondering: “What are the limits of growth?” of a tool that no one doubts, least of all non-subscribers, is destined for universal ownership. In many surveys non-subscribers mention a prevailing pressure to acquire a tool that they do not need but that they will eventually purchase. Excluding the corded telephone and, to a lesser extent, television, no other medium has had the same potential for universal use. Under pressure from other industrialized countries, the telephone became ubiquitous in France only in the 1970s, nearly a century after its invention. Unlike the corded phone and television, the mobile phone is neither revolutionary nor the harbinger of a new technological capacity. It merely reproduces existing properties of the telephone but shifts them onto new ground and into previously inaccessible situations.

How mobility impacts the flow-level performance of wireless data systems

Abstract: The potential for exploiting rate variations to increase the capacity of wireless systems by opportunistic scheduling has been extensively studied at packet level. In the present paper, we examine how slower, mobility-induced rate variations impact performance at flow level, accounting for the random number of flows sharing the transmission resource. We identify two limit regimes, termed fluid and quasistationary, where the rate variations occur on an infinitely fast and an infinitely slow time scale, respectively. Using stochastic comparison techniques, we show that these limit regimes provide simple performance bounds that only depend on easily calculated load factors. Additionally, we prove that for a broad class of fading processes, performance varies monotically with the speed of the rate variations. These results are illustrated through numerical experiments, showing that the fluid and quasistationary bounds are remarkably tight in certain usual cases